The $50 price at the Comic Con might seem excessive - but here's something to compare that to. You can not get either model as a retail set. You can build them using LDD (although not 100% as some pieces are not available in the right colors) - however the cost for the LDD model would be $39.32 ($21.60 for the Dropship, $17.72 for the AT-TE). Of course, going through Bricklink or other source for bricks would be cheaper if you have the instructions.

There is one difference, for the undercarriage (between the legs)I used 3 2x2 Round bricks to fill the spaces between the brick 1x1 Headlights where bigospedros indicated to me that he used inverted slopes.